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A strip‐typed antenna with the advantages of simple structure and easy fabrication is first proposed. When the antenna is mounted on a planar circuit board, it has the same radiation characteristics as a traditional microstrip antenna operated in the fundamental mode; however, the proposed antenna only occupies a space of a linear length for the surface of the circuit board. Then, A 1 × 4 array with ± 45° polarizations is realized using the strip‐typed antenna as a radiating element. The dual‐polarized array is excited with a pair of coplanar corporate feed networks. Simulated results show that the gains of the radiating element and array are up to 8 and 13 dBi, respectively; in addition, the isolation between the two input ports of the array is higher than 27 dB within an impedance bandwidth of around 11%. Experiments are also carried out, and they validate the simulated results. Details of the designs are presented. [ABSTRACT FROM AUTHOR]

A circularly polarized (CP) meander loop antenna used in the unmanned aerial vehicle (UAV) satellite navigation system is proposed. The planer size of the proposed antenna is 45.6 × 38.4 mm2 and it was printed on a thin flexible substrate with a thickness of only 0.063 mm. Thus, it has the advantages of a lightweight, low profile, and ease in manufacturing. The proposed antenna design utilizes a loop antenna and has applied a perturbed element into the loop to excite two equal amplitude electric fields with a 90° phase difference, thereby exciting a good CP radiation. The measured 10‐dB impedance bandwidth of the proposed antenna was 9.3% (1.48–1.624 GHz), and its corresponding 3‐dB axial ratio (AR) bandwidth was 2.3% (1.555–1.591 GHz). The CP operating band of the proposed antenna can cover the GPS L1, Galileo E1, and Beidou B1 band (1.559–1.591 GHz). [ABSTRACT FROM AUTHOR]

The design of a switchable microstrip-fed half annular ring slot antenna for multi-frequency operation is proposed. By incorporating three switches along the meandered tuning stub that is loaded on top of the half circular patch located within the circular slot, easy reconfigurability of four frequency bands over a frequency ratio of approximately 1.7:1 can be achieved. Furthermore, the proposed antenna structure does not require additional DC biasing circuit. Simulation and measurement results have demonstrated that the four frequency bands can exhibit good impedance matching, stable radiation patterns and desirable gains. [ABSTRACT FROM PUBLISHER]

The performances of a quasilumped coupler with a pair of capacitors are first described. By varying the capacitance value of the capacitors, the coupler can operate at three different modes, including uncoupled-line mode, quadrature hybrid mode, and T-junction power divider mode. Based on the coupler design, a microstrip antenna with switchable polarization is developed and implemented. Experimental results demonstrate that the reconfigurable antenna can provide two linear polarizations and one circular polarization at one frequency. In addition, the antenna operating at each polarization state has good impedance matching and broadside radiation with low cross polarization. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:471-474, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27374 [ABSTRACT FROM AUTHOR]

Abstract: The characteristics of full and half-size V-slotted triangular patch antennas with shorting walls are investigated and compared in this paper. Both the antennas are dual-frequency radiate elements and they possessed impedance bandwidth of more than 8% at each operating frequency. For the full-size case, the radiation patterns at the lower and higher operating frequencies are conical and broadside, respectively. In comparison, both the operating frequencies of the half-size case exhibited the same broadside radiation patterns. Details of the measured and simulated results are presented and discussed. [Copyright &y& Elsevier]